Hannah Bloch

Nawaz Sharif, who served until Friday as the 18th prime minister of Pakistan, is no stranger to his country's courts. In three tumultuous go-rounds as premier over the past 27 years, he's been embroiled repeatedly in judicial cases on charges ranging from corruption and contempt to terrorism and treason.

On an overcast late-spring afternoon, a group of bird lovers from the Earth Conservation Corps are in a boat on Washington, D.C.'s Anacostia River, and point out an osprey circling overhead. "This is like their summer vacation spot and where they have their young," says Bob Nixon, in the boat. "Then they spend most of their lives in the Amazon."

Amid deep strains in the U.S. relationship with Mexico, a country that's been a favorite target of President Trump, Secretary of State Rex Tillerson and Homeland Security chief John Kelly took part in talks in Mexico City on Thursday that were aimed at smoothing out tensions.

"That's going to be a tough trip," the president said Thursday morning at the White House. Some of the key issues between the two countries: immigration, border security, trade and U.S. aid to Mexico.

As Donald Trump was sworn in as the 45th U.S. president, protests, demonstrations — and a few celebrations — were underway in cities around the world.

In London, demonstrators holding anti-Trump signs gathered outside the U.S. Embassy on Friday evening. Earlier in the day, huge banners saying "Build Bridges Not Walls" were hung across the city's bridges, part of a U.K. campaign that that began after Trump was elected in November.

Back in January 2010, Patrick Meier, a Ph.D. student in international relations at Tufts University, was checking email at home, with CNN on in the background, when he was jolted by a breaking news alert. An earthquake had struck Haiti, and tens of thousands were feared dead.

For many of us, Sept. 11, 2001, is one of those touchstone dates — we remember exactly where we were when we heard that the planes hit the World Trade Center and the Pentagon. I was in Afghanistan.

I'd arrived in Kabul on Sept. 9 to cover the trial of eight foreign aid workers who had been arrested by the Taliban regime, which accused them of preaching Christianity to Afghans. Proselytizing was a death penalty crime, and two Americans were among the accused.